Slice potatoes about 1/4 in thick or about 4 mm. You need to do this as you assemble the dish or the potatoes will discolor. I use a cuisinart food processor. Or you can use a mandolin.
Rub the butter and minced garlic over the bottom and sides of the pan.
Mix the salt and white pepper together.
Have your cream at room temperature.
Grated gruyere cheese. I haven't found a good substitute for it, it's worth the extra money.
Shingle the sliced potatoes in your baking dish.
Sprinkle with salt and white pepper.
Sprinkle a even layer of cheese.
Pour about 1/2 cup of cream over the cheese.
Repeat the process, but change the pattern of the sliced potatoes.
Build 5-6 layers of potatoes, salt-pepper, cheese and cream.
Cover with plastic wrap.
And then aluminum foil, poke some holes in the top with a pairing knife. Then place in a 350 degree oven.
Bake for about 1 1/2 hours or until potatoes are tender. Take off foil and bake for another 30-45 minutes.
This is what they should look like when they are done. Let rest at room temperature for 15-20 minutes before cutting.
Serve with beef, chicken or fish. Enjoy!